Highly read on journals.elsevier.com/animal-behaviour in March–May
Selection against aggression seems to have occurred naturally in some animals and to have led to traits similar to those seen in domesticated animals.
The bonobo (Pan paniscus) is less aggressive and more sociable than its sister species, the chimpanzee (Pan troglodytes). Brian Hare at Duke University in Durham, North Carolina, and his team propose that these differences, along with a suite of physical variations — bonobos have smaller childlike heads, plus paler lips and tails, than chimps — are a linked set of traits that parallel those seen in domesticated animals such as dogs and guineapigs. Bonobos are, the authors argue, a self-domesticated ape.
Selection pressures that might have favoured bonobo self-domestication include the acquisition of bigger territories, reducing competition for food and the emergence of coalitions of females that enforced the peace.
Domestication, far from being a human invention, may also occur spontaneously in nature, they say.